1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to a remote user interface (RUI), and more particularly, to a method of an RUI server providing a user interface to an RUI client.
2. Description of the Related Art
Studies for improving a home network technology are actively being conducted by various industry standard groups, such as DLNA (Digital Living Network Alliance), HAVi (Home Audio-Video Interoperability), and UPnP (Universal Plug and Play).
In a home network, remote user interface (RUI) technology may be used for a device to control functions of another device. In brief, the RUI technology is based on a client-server architecture, in which an RUI client receives a user interface (UI) from an RUI server, such that a user can control the RUI server via the UI in the RUI client.
CEA-2014, which is the standard for an RUI, defines an UPnP network, and a protocol and frame work for an RUI in the Internet. According to CEA-2014, an UPnP device (an RUI server) provides an UI as a web page in a CE-HTML form, and a user remotely controls an application of the UPnP device through the web page. CE-HTML is a particular version of HTML and is based on XHTML.
FIG. 1 is a diagram for describing a conventional communication method between a RUI server and an RUI client according to the CEA-2014 standard.
In order to use an RUI in a home network, discovery for the RUI server should be performed first. Since CEA-2014 is based on an UPnP network, the RUI server is discovered via an UPnP discovery process. In FIG. 1, the RUI client and a control point (CP) are separately illustrated, but when an UPnP CP is embedded in the RUI client, the RUI client directly searches for the RUI server. If the CP is not embedded in the RUI client and a separate CP transmits an UI of the RUI server to the RUI client, the CP not embedded in the RUI client also searches for the RUI client via the UPnP discovery process.
After the UPnP discovery process, the RUI client obtains an UI page by referring to a uniform resource locator (URL) including the UI page in an UPnP device description. In more detail, an XHTML browser of the RUI client requests the UI page to a web server of the RUI server. Since the UI page is formed to control an application of the RUI server, the RUI client controls the application of the RUI server by using the UI page. The conventional method is described in detail in documents such as the CEA-2014 standard, and thus detailed descriptions thereof will be omitted.
As described above, a conventional RUI is based on a structure of general web server-HTML browser. The general web server does not manage access of a browser, and only returns a page that is required by the browser. Accordingly, a web server is not aware whether a request of a certain browser for a page is granted, and thus the web server cannot manage access of the RUI client.
However in the CEA-2014 standard, when the web server does not simply provide information to the RUI client but controls the provided information, i.e. functions of the RUI server through the UI page, authority of the RUI client should be controlled. This is because conflicts may occur when a user controls a device while another user controls the same device.
Accordingly, when access or session between the RUI client and the RUI server is to be managed, a separate database for managing access of each user is included in the web server, or the RUI client uses a plug-in, such as active X, for each application. However generally, a consumer electronics (CE) device uses various operating systems and does not have sufficient resources, and thus additional plug-ins cannot be freely installed.